The present invention relates to the racket which absorbs a shock or impact produced on the ball hitting net surface by the vibration absorbing member such as, for example, tennis rackets, squash rackets or the like.
This kind of conventional vibration absorbing type racket has the frame in which the buffer layer made of a gel material with the penetration value of approximately 50 to 200, such as silicone gel, is contained as a vibration absorbing means.
This type of racket is disclosed in the U.S. Pat. Application Ser. No. 161130 dated Feb. 26, 1988 and the U.S. Pat. Application Ser. No. 231211 dated Aug. 11, 1988.
In case of the racket as described above, a shock produced on the ball hitting net when a ball is hit is applied as a vibration wave to the buffer layer made of a gel material to deform said buffer layer and is thus damped. For this reason, this type of racket accompanies a problem that the shock absorbing effect will be deteriorated if the energy of shock is large.
The other kind of vibration absorbing type racket is such that the frame is provided with the mass member which is transformed by a shock energy produced on the ball hitting net and the vibration wave is thus dissipated. This type of racket is disclosed in the U.S. Pat. No. 4182512.
In case of this type of racket, a new vibration wave is often produced by a movement of the mass member and there is a problem in the vibration absorbing characteristics.
In recent years, therefore, a racket using a composite vibration absorbing member which comprises a combination of a mass member and a tacky elastic member has been offered as disclosed in the Japanese Patent Gazettes Kokai SHO 62-192182 and Kokai SHO 62-192183.
This type of racket is adapted to absorb the vibration wave by a movement of the mass member and a low repulsive deformation of a tacky elastic member and can therefore provide the satisfactory vibration absorbing characteristics.
However, the conventional composite vibration absorbing member as described above is stored in the grip part of the racket frame and the assembling and replacing works will be troublesome.